The present invention generally relates to data processing systems and more particularly to control stores included in such systems.
Many of the data processing units being developed include a so-called control store which includes a plurality of storage locations each having a control store word or so-called firmware word stored therein. The control store is used to execute a desired set of machine operations in order to achieve the required result. The control store is the heart of the control mechanism in the data processing unit. Thus, the speed of operation of the processor is directly dependent in large part on the speed of the control store. Increased speed of the control store has been accomplished in many ways, such as by use of faster memories, faster logic and various time saving techniques, including improved architecture and timing schemes. Various techniques have also been used to reduce the size of the control store to have a minimum number of locations, thereby reducing space and cost requirements, and also facilitating the use of faster memories.
It is accordingly a primary object of the present invention to provide an improved control store and associated logic for use in a data processing system.